Abstract 4177: Genetic testing for hereditary colorectal cancer syndromes in Algerian patients: A multicenter study

Background To date, 5% to 6 % of all colorectal cancers (CRCs) are associated with germline pathogenic variants in cancer predisposition genes that confer inherited predisposition to CRC. The use of genetic testing to identify individuals at risk for hereditary CRC syndromes can help to prevent the development of cancer and in the clinical management of the colorectal patients in the areas of both prevention and treatment. We report here the experience of our research laboratory of genetic testing for hereditary polyposis syndromes and Lynch syndrome (LS), respectively, in 126 patients.

Methods Fifty four (54) severe familial adenomatous polyposis (FAP) patients and 72-suspected Lynch syndrome (LS) patients, respectively, were selected from 2851 consecutive colorectal patients at five public hospitals during 2012-2019. Family histories of cancer were obtained from interviews, pedigrees and medical records of patients. Index cases and relatives diagnosed with FAP syndrome or Lynch syndrome have been tested for germline variants in APC, MLH1, MSH2, MSH6 and PMS2 genes, respectively, using PCR-Sanger Sequencing or by NGS using a cancer panel of 30 hereditary cancer genes (Color Genomics).

Results We detected 13 germline pathogenic variants in APC gene in 17 unrelated families, one germline pathogenic variant in BMPRA1 gene in juvenile polyposis syndrome (JPS) patient; seven (7) germline pathogenic variants and 2 variants of uncertain clinical significance (VUS) in MMR genes. Interestingly, 4 novel germline pathogenic variants in APC gene and 3 novel germline pathogenic variants in MMR genes, respectively, have been detected in our study. The most occurring germline pathogenic variants in APC gene were c.3927_3931del and c.4728dup that were identified in four and two index cases in 6 unrelated FAP families, respectively. In Lynch syndrome patients, the rare germline pathogenic variant MLH1 c.1546C>T has been found in 21 individuals from 9 LS families, 6 of them related, with two large kindreds. In addition, the recurrent germline pathogenic variant MSH2 c.942+3A>T has been detected in five unrelated index cases with a strong family history of LS syndrome. Moreover, the rare germline VUS PMS2 c.989-107_989-106insA has been detected in 14 unrelated LS patients and could be reclassified as likely benign. Interestingly, our NGS analysis detected the novel BMPR1A pathogenic variant c.1474-1G>C in young JPS patient that has been misdiagnosed as FAP. The in-silico analysis for this novel variant showed an alteration of the wild type acceptor site and an activation of a cryptic acceptor site, respectively, most probably affecting splicing.

Conclusions Our current study will contribute to the molecular genetics characterization of hereditary colorectal cancer syndromes in Algerian population that is relevant for clinical management in the areas of genetic testing, early diagnosis, treatment and prevention.

Citation Format: Farid Cherbal, Asma-Lamia Boumehdi, Feriel Khider, Karima Landelouci, Abdelwahab Zemam, Sarah Sabri, Adam.Walid Damache, Mohammed Oukkal, Hassen Mahfouf, Ferhat Zebboudj, Mustapha Maaoui. Genetic testing for hereditary colorectal cancer syndromes in Algerian patients: A multicenter study. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4177.

Middle East and North Africa Registry to Characterize Rate of RAS Testing Status in Newly Diagnosed Patients with Metastatic Colorectal Cancer

BACKGROUND

Rat sarcoma virus mutational status guides first-line treatment in metastatic colorectal cancer. This study was a multi center, multi-country ambispective, observational study in the Middle East and North Africa assessing regional rat sarcoma virus testing practices in newly diagnosed patients.

METHODS

The retrospective arm (2011-2014) included adults with metastatic colorectal cancer who had initiated first-line therapy with ≥1 post-baseline visit and survival data. The prospective arm (2014-2019) enrolled newly diagnosed patients with histologically proven metastatic colorectal cancer with ≥1 measurable lesion per Response Evaluation Criteria in Solid Tumors, and tissue availability for biomarker analysis. Data look-back and follow-up were 2 years; the rate of RAS mutation was evaluated.

RESULTS

RAS testing was ordered for patients in retrospective (326/417) and prospective (407/500) studies. In the former, testing was typically prescribed after first-line treatment initiation, significantly more in patients with stage IV disease (P < .005), resulting in the addition of targeted therapy (41.8% anti-epidermal growth factor receptor, 30.2% anti-vascular endothelial growth factor) in wild-type metastatic colorectal cancer, and significantly impacted the treatment of left-sided tumors (P = .037). In the latter, 58.4% were RAS wild-type; 41.6% were RAS mutant. Non-prescription of RAS testing was attributed to test unavailability, financial, or medical rea sons; predictors of testing prescription were older age, primary tumor in ascending colon, and high tumor grade. RAS status knowledge resulted in the addition of anti-vascular endothelial growth factor (20.4%) or anti-epidermal growth factor receptor therapy (21.2%).

CONCLUSION

Before 2014, RAS testing in patients with colorectal cancer in the Middle East and North Africa was often performed after first-line treatment. Testing is more routine in newly diagnosed patients, potentially shifting early treatment patterns.

Neoadjuvant endocrine therapy with or without palbociclib in low-risk patients: a phase III randomized double-blind SAFIA trial

BACKGROUND

The most prevalent subtype of breast cancer (BC) is luminal hormonal-positive breast cancer. The neoadjuvant chemotherapy regimens have side effects, emphasizing the need to identify new startegies.

OBJECTIVE

Analyze the complete pathologic response (pCR) rate and overall response in a low-risk hormone-positive subset of patients receiving neoadjuvant hormone treatment (NAHT) with or without Palbociclib (a CDK4/CDK6 inhibitor) to boost NAHT effectiveness.

MATERIALS AND METHODS

Based on the upfront 21-gene Oncotype DX or low-risk Breast Recurrence Score assay (RS™), the SAFIA trial is designed as a prospective multicenter international, double-blind neoadjuvant phase-III trial that selects operable with luminal BC patients that are HER2-negative for the induction hormonal therapy with Fulvestrant 500 mg ± Goserelin (F/G) followed by randomization of responding patients to palbociclib versus placebo. The pCR rate served as the study's main outcome, while the secondary endpoint was a clinical benefit.

RESULTS

Of the 354 patients enrolled, 253 initially responded and were randomized to either F/G fulvestrant with palbociclib or placebo. Two hundred twenty-nine were eligible for the evaluation of the pathologic response. No statistically significant changes were observed in the pCR rates for the patients treated with the F/G therapy with placebo or palbociclib (7% versus 2%, respectively) per the Chevallier classification (Class1 + Class2) (p = 0.1464) and 3% versus 10% assessed per Sataloff Classification (TA, NA/NB) (p = 0.3108). Palbociclib did not increase the rate of complete pathological response.

CONCLUSION

Neoadjuvant hormonal therapy is feasible in a selected population with a low RS score of < 31 CLINICAL TRIAL: NCT03447132.

Germline variants screening of MLH1, MSH2, MSH6 and PMS2 genes in 64 Algerian Lynch syndrome families: The first nationwide study

Colorectal cancer is the second leading cause of cancer-related deaths in women and men in Algeria. Lynch syndrome (LS) is an autosomal dominant disease caused by heterozygous germline pathogenic variants in mismatch repair genes (MMR) and frequently predisposes to colorectal cancer. However, data about MMR germline pathogenic variants in Algerian patients are limited. This first nationwide study aims to describe clinicopathologic features and germline variants in MMR genes in Algerian families with suspected LS. Sixty-four (64) families with suspected LS were studied. Index cases with LS who fulfilled Amsterdam criteria were screened by PCR-direct sequencing for germline variants in MMR genes: MLH1 (exons 1, 9, 10, 13, 16), MSH2 (exons 5, 6, 7, 12), MSH6 (exons 4 and 8) and PMS2 (exons 6 and 10). We selected these specific risk exons genes since they have a higher probability of harboring pathogenic variants. In addition, two unrelated LS patients were screened by next-generation sequencing using a cancer panel of 30 hereditary cancer genes. Six germline pathogenic variants and one germline likely pathogenic variant were identified in 19 (29.68%) families (4 MLH1, 2 MSH2 and 1 MSH6). Of index cases and relatives who underwent genetic testing (n = 76), 30 (39.47%) had MMR pathogenic gene variants, one (0.13%) had MMR gene likely pathogenic variant and three had MMR variant of uncertain significance, respectively. Two novel germline pathogenic variants in MLH1 (2) and one germline likely pathogenic variant in MSH6 (1) never published in individuals with LS have been detected in the present study. The recurrent MLH1 germline pathogenic variant c.1546C>T has been found in nine LS families, six of them related with two large kindreds, from four North central provinces of Algeria. In addition, the common MSH2 germline pathogenic variant c.942+3A>T has been detected in five unrelated patients with a strong LS family history. The accumulative knowledge about clinicopathological and genetic characteristics of LS in Algerian patients will impact clinical management in the areas of both prevention and treatment.

Abstract 1451: BRCA1 and BRCA2 germline mutational spectrum in Algerian triple negative breast cancer (TNBC) patients

Background: Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. To date, triple negative breast cancer (TNBC) shows substantial overlap with basal type cancer and it is associated with aggressive tumor behavior, poor prognosis and BRCA1 mutations. In the present study, we screened for the prevalence of BRCA1 and BRCA2 germline mutations in a cohort of 169 TNBC patients using PCR-Sanger sequencing and NGS with a cancer panel of 30 hereditary cancer genes or BRCA1/BRCA2 genetic test.

Materials and Methods: 169 TNBC patients and their relatives were referred trough several public hospitals from six years (2013-2019). BRCA1 germline mutation was screened using PCR-Sanger sequencing in 66 TNBC patients with strong family history of breast and ovarian cancer and 103 sporadic TNBC patients including all exons where a mutation was previously found in Algerian population (exons 2, 3, 4, 10, 17 and 19). BRCA2 germline mutation was screened using PCR-Sanger sequencing in 24 TNBC patients with strong family history of breast cancer including all exons where a mutation was previously found in Algerian patients (exons 10 and 22). In addition, nine (9) TNBC patients with strong family history of breast and ovarian cancer were analyzed by NGS using BRCA1 and BRCA2 test or a cancer panel of 30 hereditary genes (Colors genomics).

Results: The analysis of the genomic DNA samples of 169 TNBC patients revealed that 15 patients carried pathogenic germline variants in BRCA1 gene and three patients carried pathogenic variants in BRCA2 gene (10.65%). Eight distinct germline mutations in BRCA1 have been detected in this study: c.83_84delTG, c.181T&gt;G, c.798_799delTT, c.505C&gt;T, c.923_924delGC, c.2125_2126insA, c.5257A&gt;G and deletion of exon 15. Interestingly, the recurrent and specific mutation c.83_84delTG has been detected in 4 unrelated TNBC patients. The pathogenic variant c.2125_2126insA has been detected in three unrelated families and also in the first relatives of 2 patients. The rare likely pathogenic variant BRCA1 c.5257A&gt;G/p.Arg1753Gly has been detected in young female TNBC patient. The Del exon 15 in BRCA1 has been detected in two unrelated patients. Three distinct germline mutations in BRCA2 have been detected in three TNBC patients: c.1813dupA, c.7654dupA and c.8485C&gt;T. Interestingly, these three mutations are reported for the first time in Algerian population. The c.1813dupA and c.8485C&gt;T pathogenic variants have been detected in two young female TNBC patients with a family history of male breast cancer.

Conclusions: In the current study, we detected recurrent germline mutations in BRCA1 gene in early onset TNBC patients. BRCA2 pathogenic variants have also been detected in young female TNBC patients. TNBC immunophenotype should be considered as an additional criterion for genetic counselling and testing of BRCA genes in Algerian women with early onset breast cancer.

Citation Format: Farid Cherbal, Chiraz Mehemmai, Hadjer Gaceb, Hassen Mahfouf, Kada Boualga. BRCA1 and BRCA2 germline mutational spectrum in Algerian triple negative breast cancer (TNBC) patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1451.

Final result for SAFIA trial for neoadjuvant palbociclib in patients with operable luminal breast cancer responding to fulvestrant

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Background: Luminal, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC) encompasses the most common subtype of breast malignancies. Neoadjuvant strategies of operable BC are primarily based upon chemotherapy (CT), while neoadjuvant hormone therapy (NAHT) has not been well studied in the Middle East and North Africa (MENA) region. However, these tumors might respond poorly to neoadjuvant CT with significant side effects, emphasizing the need to identify patients who could be candidates for NAHT. Methods: The SAFIA trial is a prospective multicentre, international, double-blind, neoadjuvant phase-III trial using upfront 21-gene Oncotype DX Breast Recurrence Score assay (RS) <31) to select operable Luminal HER2-negative patients for induction hormonal therapy with Fulvestrant 500 mg +/– Goserelin (F/G) before randomizing responding patients to F/G + Palbociclib (Cyclin-Dependent Kinase 4/6 inhibitor / CDK 4/6) versus F/G + Placebo. The primary endpoint of this study was the complete pathologic response (pCR) rate. Results: A total of 354 patients were enrolled, leading to 277 patients treated with induction F/G. Of these, 253 responding patients were randomized to F/G fulvestrant with palbociclib or Placebo. Two hundred and thirty patients were evaluable for pathologic response. No statistically significant differences were identified in terms of pCR rates between F/G with palbociclib or placebo: 2% versus 7%, respectively. According to the radiologic responses post- induction F/G, the hormone sensitivity rate was 89.8%, while the clinical benefit of 8–9 months of neoadjuvant F/G was 96%. Safety in the MENA population was acceptable with a grade 3-4 neutropenia rate of 25% in the F/G plus palbociclib arm. The feasibility of performing the 21-gene breast recurrence score assay on core biopsy specimens was optimal in 96.4% of cases. Conclusions: The addition of palbociclib to neoadjuvant F/G did not show any additional benefit in terms of pathologic response, including pCR in neoadjuvant therapy of Luminal HER2-negative BC responding to induction F/G. The use of an upfront 21-gene assay appeared feasible on biopsy specimens, and the identification of tumors with RS<31 allowed to select endocrine sensitive patients, leading ultimately to a 96% clinical benefit with 8–9 months of F/G neoadjuvant therapy. Clinical trial information: NCT03447132. [Table: see text]

Response to Induction Neoadjuvant Hormonal Therapy Using Upfront 21-Gene Breast Recurrence Score Assay-Results From the SAFIA Phase III Trial

Luminal, human epidermal growth factor receptor 2–negative breast cancer represents the most common subtype of breast malignancies. Neoadjuvant strategies of operable breast cancer are mostly based on chemotherapy, whereas it is not completely understood which patients might benefit from neoadjuvant hormone therapy (NAHT).

Epidemiology of breast cancer in women based on diagnosis data from oncologists and senologists in Algeria

BACKGROUND

Breast cancer (BC) is a major health issue threatening women's life. No reliable epidemiological data on BC diagnosed by oncologists/senologists are available in Algeria.

METHODS

The BreCaReAl study, a non-interventional prospective cohort study, included adult women with confirmed BC in Algeria. Disease incidence, patients and disease characteristics, treatment patterns, and mortality rate were recorded up to 12 months of follow-up.

RESULTS

Overall, 1,437 patients were analysed: median age was 48 [41;57] years and 337 (23.5%) women had a family history of BC. BC incidence was 22.3 (95% CI: 21.5; 23.2) cases per 100,000 inhabitants over 8 months. Delayed diagnosis was reported in 400 (29.2%) patients. First line of treatments were mainly chemotherapy and surgery. Twenty-eight serious adverse events were reported including 10 (37.0%) events which led to death. Mortality rate reached 3.2% at 12 months CONCLUSION: A delayed diagnosis highlights the importance of implementing more effective screening strategies.

Incidence of lung cancer in males and females in Algeria: The lung cancer registry in Algeria (LuCaReAl)

BACKGROUND

Lung cancer is a major cause of death worldwide. However, few data on incidence, histologic types and mortality rates of lung cancer were available for Algeria.

METHODS

LuCaReAl is an ongoing descriptive, non-interventional, national, multicenter, prospective and longitudinal study conducted in Algeria, among oncologists and pulmonologists in public community and university hospitals. Median and interquartile ranges are displayed.

RESULTS

Between July 2016 and July 2017, 897 patients were included. Overall incidence of lung cancer was 3.4 [3.2;3.6] cases per 100,000 inhabitants; overall incidence by sex was 5.8 [5.4;6.2] for males and 1.0 [0.8;1.1] for females. Adenocarcinoma was the most common histologic type of cancer. Most tumors were diagnosed at Stage IV.

CONCLUSION

The first results from the LuCaReAl study in Algeria showed that most patients are diagnosed with lung cancer at an advanced stage. The ongoing follow-up will next provide data on the survival and mortality rates.

Prospective evaluation of current RAS mutation testing practices in newly diagnosed metastatic colorectal cancer: Middle East and North Africa Registry (MORE-RAS) Study

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Background: RAS testing is essential for treatment selection in metastatic colorectal cancer (mCRC), as anti-EGFR treatment is indicated only in patients with wild-type (WT) RAS. MORE-RAS was a multicenter, multicountry, observational, ambispective (retrospective + prospective) study designed to evaluate RAS mutation status among patients with mCRC in the Middle East and North Africa (MENA) region. Results of the retrospective study over a prior 2-year period have been previously presented. Here, we report on the prospective evaluation of testing practices in newly diagnosed patients from the same centers. Methods: Five countries (Algeria, Egypt, KSA, Kuwait, Lebanon) enrolled patients between Dec 2014 and Feb 2019. Patients with a new diagnosis of histologically proven mCRC, at least 1 measurable lesion per RECIST criteria, and tissue availability for biomarker analysis were included; those with co-existing malignancies or life expectancy < 6 months were excluded. The primary endpoint was evaluation of the rate of RAS mutation in newly diagnosed patients. Follow-up was for 2 years. Results: 500 patients (mean age 54.6 years; 58% female) were included; 96.4% had Stage 4 disease. Primary tumor sites were sigmoidal colon: 33.4%; rectum: 29.6%; ascending colon: 18.4%; descending colon: 11.4%; transverse colon: 5.2%; and unknown: 1.4%. Most frequent sites of metastasis were liver: 43.4%, lung: 16.0%, and peritoneum: 10.1%. Overall, 407 pts (81.4%; 95% CI, 78%–85%) received prescription for RAS testing. RAS WT was found in 58.4% and mutant in 41.6%; the test was inconclusive in 1 pt. Non-prescription was attributed to test unavailability and medical or financial reasons. The distribution of mutations was KRAS: 85%, NRAS: 4.9%, and not available: 10.1%. Predictors of RAS testing prescription were older age, primary tumor localization in ascending colon, and high tumor grade. Knowledge of RAS status resulted in the addition of bevacizumab or anti-EGFR therapy in 20.4% and 21.2% of pts, respectively at Visit 1 (baseline). Conclusions: RAS testing is now routinely prescribed for newly diagnosed mCRC in the MENA region and can change therapy patterns. The RAS mutation rate in this region differs from that in Western countries.

Abstract 2208: Clinicopathological and genetic study of ovarian cancer in Algerian women: First report

Background: Ovarian cancer represents the fourth most common cause of mortality among Algerian women. Of all gynecological malignancies, ovarian cancer causes the highest number of deaths in women in Algeria. In the present study, we sought to determine for the first time, clinical, tumor and genetic characteristics associated with ovarian cancer in Algerian women. We also screened for specific mutations in BRCA1 and BRCA2 genes in patients with positive family history of ovarian cancer.

Materials and Methods: The study population included 244 patients diagnosed with ovarian cancer. Ovarian carcinomas were diagnosed between 2011 and 2016. Data were collected from cancer registries of public hospitals that covered 10 provinces of Algeria. Patient and tumor information included: age at diagnosis, histological type, histological grade, TNM stage, preoperative tumors markers CEA and CA-125 serum levels, family history with ovarian cancer or any cancer, age at menarche, oral contraception and breast feeding. BRCA1 exon 11 and BRCA2 exon 22 were screened by PCR-direct sequencing in 11 patients with a family history of ovarian cancer for two common mutations that were previously found in Algerian population, respectively.

Results: The median age at diagnosis cancer was 51.02 years. The mean age at menarche was 13.04 years. We noticed that 43.85 % of women have been diagnosed with ovarian cancer at younger age (&lt; 50 years). The proportion of ovarian cancer patients with premenopausal status was 39.75%. The commonest histological subtypes was serous adenocarcinoma (52.45%) followed by endometrioid (10.65%), mucinous (9.43%) and clear cell carcinoma (4.09%). We found that the proportion of tumors with histological grade II (41.8%) and grade III (27.86%) was commonest in 70% of the patients. Our results showed that 61.46% of the patients were diagnosed at stage II (39.34%), stage III (8.6%) and stage IV (13.52%), respectively. 73.36% and 18.08% of the patients were positive for CA-125 and CEA, respectively. We noticed that 29 patients (11.88%) had a positive family history of ovarian cancer. 141 patients (57.78%) had breastfed and 107 patients (43.85%) were using contraception.The BRCA1 mutation c.2125_2126insA and BRCA2 mutation c.8940delA have not been detected in our patients.

Conclusions: For the first time, we report here some clinical, biological, tumor and genetic characteristics of ovarian cancer in Algerian women. Our study showed that ovarian cancer in Algerian women has some similar clinicopathological and biological features with women of European descent. Interestingly, the median age of diagnosis in ovarian cancer patients was younger than average age in Europe and America. High frequency of patients with positive family history of ovarian cancer could be linked to genetic background of Algerian population. Further studies are needed to reaffirm our findings. BRCA1 and BRCA2 analysis are ongoing in our patients.

Citation Format: Farid Cherbal, Chiraz Mehemmai, Lamia Boumehdi, Feriel Khider, Amina Boucheffa, Hadjer Gaceb, Hassen Mahfouf, Rabah Bakour. Clinicopathological and genetic study of ovarian cancer in Algerian women: First report [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2208.

Distribution of molecular breast cancer subtypes among Algerian women and correlation with clinical and tumor characteristics: a population-based study

BACKGROUND

Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. Molecular classification of breast cancer is an important factor for prognosis and clinical outcome. There are limited data regarding molecular breast cancer subtypes among Algerian women. The objective of the present study was to analyze the proportion and distribution of molecular subtypes and to determine their associations with some clinical and tumor characteristics: age at diagnosis, menopausal status, histological type and histological grade.

MATERIALS AND METHODS

The study population included 3014 female breast cancers. We analyzed breast cancers from cancer registries of academic medical oncology service of public hospital of Rouiba, anticancer center of Blida, and anticancer center of Batna. Breast cancers were diagnosed between 2008 and 2013. Molecular subtype classification was done based on immunohistochemical surrogates for ER (Estrogen receptor), PR (Progesterone receptor) and HER2 (human epidermal growth factor receptor-2) status obtained from medical records for 3014 breast cancer patients. Breast cancer subtypes definitions were as follow: Luminal A (ER+ and/or PR+, HER2-), Luminal B (ER+ and/or PR+, HER2+), TNBC (ER-, PR - , HER2-), HER2+ (ER-, PR-, HER2+). Molecular subtypes were correlated with the clinicopathological characteristics of the tumors.

RESULTS

The mean age at diagnosis cancer was 48.5 years. Proportions of the luminal A, TNBC, luminal B and HER2+ breast cancer subtypes were 50.59%, 20.80%, 19.67% and 8.92%, respectively. We noted a significant difference in the distribution of age at diagnosis among the four cancer subtypes (P= 0.004). Luminal A, Luminal B, TNBC and HER2+ subtypes were significantly different by premenopausal and postmenopausal status (P= 0.01). Invasive Ductal Carcinoma was the most common histological type in all breast cancer subtypes. Tumors with histological grade 2 and 3 were more common in patients for the four breast cancer subtypes.

CONCLUSIONS

For the first time, we report the distribution of molecular breast cancer subtypes and their associations with some clinicopathological characteristics in a large cohort of Algerian women. In our current study, the median age of diagnosis for all breast cancer subtypes was younger than the average age in Europe and America. Luminal A was the most common sub- type in our patients followed by TNBC. The proportion of luminal A subtype was lesser than reported in white women with breast cancer in Europe and America. The proportion of TNBC subtype in Algerian women was higher compared with Caucasian women of European ancestry. This study will contribute in developing optimal clinical trial protocols and personalized management strategies for Algerian breast cancer patients.

Abstract 5284: Triple-negative breast cancer in Algerian population: clinicopathological and molecular study

Background:Triple-negative breast cancer (TNBC),defined by the absence of estrogen receptor (ER), progesterone receptor (PR),and human epidermal growth factor receptor 2 (HER2) expression, accounts for 12% to 20% of all breast cancers.Its prevalence differs between races.TNBC shows substantial overlap with basal-type and BRCA1-related breast cancers and it is associated with early recurrence of disease and poor outcome.In the current study, we sought to compare some clinical and tumor characteristics of breast cancer patients with or without TNBC. We also screened for the prevalence of germline BRCA1 mutations in TNBC patients. Materials and Methods: Clinical and tumor characteristics data of 3403 breast cancer patients were collected from cancer registries of anticancer center of Blida, public hospital of Oued Amizour, anticancer center of Batna and public hospital of Rouiba. Breast cancers were diagnosed between 2007 and 2014. All histopathologic and immunohistochemical diagnoses were reviewed by pathologists. Patients were divided in two groups: those with TNBC and those with other breast cancer subtypes. Differences between the two groups with regard to clinicopathologic parameters: age at diagnosis, menopausal status, histological grade and histological type, were examined using Chi-square test. BRCA1 was screened by PCR-direct sequencing in 56 TNBC patients (26 with a family history of breast cancer and 30 sporadic cases) including all exons where a mutation was previously found in Algerian population (exons 2, 3, 5, 11). Results: The median age at diagnosis for TNBC and non-TNBC patients was 46.96 years and 49.01 years, respectively.The overall prevalence of TNBC was 21.65% (737/3403). Our data showed significant differences in the distribution of age at diagnosis (P&lt;0.0005) and tumor histological grade (P&lt;0.0001) between TNBC and non-TNBC patients.Among tumor with histological grade III,TNBC accounted for 50.54% for all TNBC patients and non-TNBC accounted for 25.28% for all non-TNBC patients.Premenopausal women accounted for 60.71% and 58.9% for all TNBC patients and all non-TNBC patients, respectively. Our data analysis revealed no difference in the distribution of histological tumor type between the two groups.Two BRCA1 mutations, c.83_84delTG and c.2125_2126insA have been detected in two young TNBC patients with a family history of breast cancer. Interestingly, the mutation c.2125_2126insA has been detected in 4 relatives of TNBC proband.Conclusions:This largest Algerian population-based study showed that the prevalence of TNBC in Algerian women is similar to that in African-American patients and higher than reported in white women in Europe and America. The high prevalence of TNBC in Algerian women compared to western countries could be linked to environmental factors and genetic background. Further research is needed to determine long term survival rates in the two groups of breast cancer patients.

Citation Format: Farid Cherbal, Hadjer Gaceb, Chiraz Mehemmai, Insaf Saiah, Rabah Bakour, Abdelhalim Ould-Rouis, Tarek Touahria, Hassen Mahfouf, Samia Daoudi, Wassila Benbrahim, Kada Boualga. Triple-negative breast cancer in Algerian population: clinicopathological and molecular study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5284. doi:10.1158/1538-7445.AM2015-5284

Capecitabine combined with oxaliplatin (XELOX) as first-line chemotherapy in colorectal cancer with liver metastases

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Background: The combination of 5-fluorouracil (5-FU), leucovorin (LV), and oxaliplatin (I-OHP) was shown to be both more active against metastatic colorectal carcinoma and better tolerated. Methods: Chemotherapy-naive patients confirmed histologic colorectal cancer with liver metastases, adequate born morrow, renal and hepatic function, measurable diseases were considered eligible for the study. Treatment: Six cycles of oxaliplatin 85 mg/m2 day1 plus capecitabine 1250 mg/m2 twice daily days 1–14 every 21 days Results: Twenty six patients were evaluated for safety and efficacy (male/female, 12/14). Median age was 53 years (range 32–75 years). A total of 142 cycles have been administered: median per patient 4 (range 3–6 courses). In an intent-to-treat efficacy analysis, One complete and ten partial responses were achieved [overall objective response rate (ORR): 42, 3%; whereas 7 patients had stable disease and eight patients had progressive disease. Seven patients from 11 with objective response underwent major liver resection: 2 bisegmentectomy, 1 left lobectomy, 4 segmentectomy, and receive the same regimen of chemotherapy (Six cycles) as an adjuvant treatment and still alive without recurrence. The overall survival (OS) was 19, 2 months. The median response duration was 7 months. The median time to progression (TTP) was 8 months. The grade 3 toxicities were diarrhea (7%), fatigue (4%), neurotoxicity (2%), neutropenia (2%), and thrombocytopenia 4%). Conclusions: The combination of oxaliplatin and capecitabine is safe and has a promising activity in patients with liver metastatic colorectal carcinoma.

No significant financial relationships to disclose.